Cam cap

ABSTRACT

A cam cap may include an oil supply circuit formed to the cam cap for supplying hydraulic pressure to a continuously variable valve timing and an oil flowing backward preventing unit disposed to the oil supply circuit for preventing operation oil from flowing backward.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims priority to Korean Patent Application No. 10-2008-0122133 filed on Dec. 3, 2008, the entire contents of which are incorporated herein for all purposes by this reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a cam cap. More particularly, the present invention relates to a cam cap that prevent from flowing backward to a continuous variable valve timing.

2. Description of Related Art

A variable valve timing (CVVT; continuous variable valve timing) is a apparatus for controlling valve opening timing by supplying operation oil according to engine operation conditions and it can enhance fuel consumption efficiency.

The CVVT is operated by supplied oil from advance/retard oil supply lines of an oil control valve (OCV; oil control valve).

However, repeated supplying and blocking operation oil can induce oil flowing backward resulted of pulsating pressure in the oil supply lines of the OCV and also fluctuation of oil pressure in the CVVT can be occurred.

In a conventional cam cap is provided with a hydraulic pump of which capacity is increased for maintaining over minimum oil pressure that can prevent from flowing backward.

However, excessive capacity of the hydraulic pump for preventing from fluctuation of oil pressure can induce fuel consumption deterioration.

The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.

BRIEF SUMMARY OF THE INVENTION

Various aspects of the present invention are directed to provide a cam cap that prevent from fluctuation of oil pressure.

A cam cap may include an oil supply circuit formed to the cam cap for supplying hydraulic pressure to a continuously variable valve timing, and an oil flowing backward preventing unit disposed to the oil supply circuit for preventing operation oil from flowing backward.

The oil flowing backward preventing unit may include a flowing backward preventing hole that includes an inlet channel for supplying the hydraulic pressure and an outlet channel for exhausting the hydraulic pressure from the inlet channel and is disposed to the oil supply circuit, and a flowing backward preventing member disposed in the flowing backward preventing hole and selectively blocking the flowing backward preventing hole according to a flow direction of the operation oil.

The flowing backward preventing member may include a plunger provided with a chamber therein and at least an oil opening is formed to a side of the plunger for supplying a backward hydraulic pressure into the camber so as to move the plunger into the inlet channel when a backward flow of the operation oil occurs in the flowing backward preventing hole.

The flowing backward preventing member may include a plunger having a main body and a protrude portion protruded from the main body, the plunger being movably disposed in the flowing backward preventing hole such that the protrude portion selectively blocks the inlet channel according to a flow direction of the operation oil, wherein the protrude portion protrudes from the main body with a predetermined thickness in a radial direction of the main body.

The plunger may be provided with a chamber therein and at least an oil opening is formed to a lateral side of the protrude portion to communicate with the camber with the flow backward preventing hole therethrough for supplying a backward hydraulic pressure into the camber when a backward flow of the operation oil occurs, wherein the plunger includes an upper opening formed on an upper portion of the plunge to communicate the chamber with the flow backward preventing hole therethrough, and wherein an auxiliary flow channel is formed at a junction portion of the inlet channel and the outlet channel and supply the backward hydraulic pressure to the chamber through the upper opening.

The plunger may be provided with a chamber therein and includes an upper opening formed on an upper portion of the plunge to communicate the chamber with the flow backward preventing hole therethrough, wherein an auxiliary flow channel is formed at a junction portion of the inlet channel and the outlet channel and supply the backward hydraulic pressure to the chamber through the upper opening.

A lower end portion of the main body may be shaped of a cone for smoothly supplying the hydraulic pressure between the inlet and outlet channels.

The inlet channel and the outlet channel of the flowing backward preventing hole may be substantially vertical to each other.

A check valve for preventing the hydraulic pressure from being supplied from the outlet channel to the inlet channel may be disposed to the flowing backward preventing portion.

In another aspect of the present invention, the cam cap may include an oil supply circuit formed to the cam cap for supplying hydraulic pressure to a continuously variable valve timing, an oil control valve disposed to the cam cap to selectively supply operation oil to the continuously variable valve timing, a flowing backward preventing hole that includes an inlet channel for supplying the hydraulic pressure and an outlet channel for exhausting the hydraulic pressure from the inlet channel and is disposed to the oil supply circuit, and a flowing backward preventing member disposed in the flowing backward preventing hole and selectively blocking the flowing backward preventing hole according to a flow direction of the operation oil.

The inlet channel and the outlet channel of the flowing backward preventing hole may be substantially vertical to each other.

The flowing backward preventing member includes a plunger provided with a chamber therein and at least an oil opening may be formed to a side of the plunger for supplying a backward hydraulic pressure into the camber so as to move the plunger into the inlet channel when a backward flow of the operation oil occurs in the flowing backward preventing hole, wherein the plunger includes a main body and a protrude portion protruded from the main body, the plunger being movably disposed in the flowing backward preventing hole such that the protrude portion selectively blocks the inlet channel according to a flow direction of the operation oil, and wherein a lower end portion of the main body is shaped of a cone for smoothly supplying the hydraulic pressure between the inlet and outlet channels.

A check valve, for preventing the hydraulic pressure from supplied from the outlet channel to the inlet channel, may be disposed to the flowing backward preventing portion.

The methods and apparatuses of the present invention have other features and advantages which will be apparent from or are set forth in more detail in the accompanying drawings, which are incorporated herein, and the following Detailed Description of the Invention, which together serve to explain certain principles of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an exemplary cam cap according to the present invention.

FIG. 2 is a perspective view of an exemplary cam cap without an oil control valve and a continuously variable valve timing according to the present invention.

FIG. 3 is a cross-sectional view along line III-III of FIG. 2.

FIG. 4 is a partial cross-sectional view along line III-III of FIG. 2.

FIG. 5 is a perspective view of an exemplary plunger according to the present invention.

FIG. 6 is a cross-sectional view of an exemplary cam cap according to the present invention.

It should be understood that the appended drawings are not necessarily to scale, presenting a somewhat simplified representation of various features illustrative of the basic principles of the invention. The specific design features of the present invention as disclosed herein, including, for example, specific dimensions, orientations, locations, and shapes will be determined in part by the particular intended application and use environment.

In the figures, reference numbers refer to the same or equivalent parts of the present invention throughout the several figures of the drawing.

DETAILED DESCRIPTION OF THE INVENTION

Reference will now be made in detail to various embodiments of the present invention(s), examples of which are illustrated in the accompanying drawings and described below. While the invention(s) will be described in conjunction with exemplary embodiments, it will be understood that present description is not intended to limit the invention(s) to those exemplary embodiments. On the contrary, the invention(s) is/are intended to cover not only the exemplary embodiments, but also various alternatives, modifications, equivalents and other embodiments, which may be included within the spirit and scope of the invention as defined by the appended claims.

FIG. 1 is a perspective view of an exemplary cam cap according to the present invention and FIG. 2 is a perspective view of an exemplary cam cap without an oil control valve and a continuously variable valve timing according to the present invention.

FIG. 3 is a cross-sectional view along line III-III of FIG. 2.

Referring to FIG. 1 to FIG. 3, a cam cap 100 according to an exemplary embodiment of the present invention includes an oil supply circuit 200 formed to the cam cap 100 for supplying hydraulic pressure to a continuously variable valve timing (CVVT) 10 and an oil control valve (OCV) 20 disposed to the cam cap 100.

The oil control valve 20 selectively supplies operation oil to the continuously variable valve timing 10 through an advance hydraulic pressure supply line 30 or a retard oil supply line 40 according to operation conditions of an engine.

The cam cap according to the present exemplary embodiment includes a flowing backward preventing hole 130 that includes an inlet channel 110 for supplying hydraulic pressure and an outlet channel 120 for exhausting hydraulic pressure and is disposed to the oil supply circuit 200 and a flowing backward preventing member 140 disposed to the flowing backward preventing hole 130.

The flowing backward preventing member 140 includes a plunger 141 that is movably disposed in the flowing backward preventing hole 130.

The inlet channel 110 and the outlet channel 120 of the flowing backward preventing hole 130 are substantially vertical to each other.

FIG. 5 is a perspective view of a plunger according to the present exemplary embodiment.

Referring to FIG. 5, the plunger 141 includes a main body 143 and a protrude portion 145 protruded from the main body, and the protrude portion 145 selectively blocks the inlet channel 110.

The plunger 141 is provided with a chamber 147 therein and an oil opening 149 is formed to a side of the plunger 141 for supplying hydraulic pressure into the camber 147 when flowing backward is generated.

A cone 151 is formed to an end of the main body 143 for smoothly supplying hydraulic pressure to the inlet channel 110.

FIG. 4 is a partial cross-sectional view along line III-III of FIG. 2.

In another exemplary embodiment of the present invention, the main body 143 may include an upper opening 150 formed at an upper portion of the plunger 141 to communicate with the outlet channel 120 through an auxiliary flow channel 153.

Referring to FIG. 3 and FIG. 4, hereinafter, operations of the cam cap according to the present exemplary embodiment will be explained.

As shown in FIG. 3, if the operation oil is supplied normally, the plunger 141 does not prevent the operation oil from flowing from the inlet channel 110 to the outlet channel 120.

However, when the oil control valve 20 selectively supplies operation oil to the continuously variable valve timing 10 through an advance hydraulic pressure supply line 30 or a retard oil supply line 40 according to operation conditions of an engine, flowing backward may be occurred due to fluctuation of oil pressure.

When flowing backward is occurred, the operation oil can flow from the outlet channel 120 to the inlet channel 110.

And then, the operation oil flows into the chamber 147 through the oil opening 149 and the upper opening 150 formed to the plunger 141 and the plunger 141 moves downward as shown in FIG. 4, and the protrude portion 145 of the plunger 141 blocks the inlet channel 110.

Thus, the flowing backward of the operation oil due to fluctuation of oil pressure can be prevented.

FIG. 6 is a cross-sectional view of a cam cap according to another exemplary embodiment of the present invention.

The plunger 141 of the cam cap according to the first exemplary embodiment is changed to a check valve in the present exemplary embodiment of the present invention.

That is, the flowing backward preventing member 140 according to the present exemplary embodiment includes a check valve 160 for preventing hydraulic pressure from supplying from the outlet channel 120 to the inlet channel 110.

Operations and other scheme of the cam cap according to the second exemplary embodiment of the present invention are similar to that of the first exemplary embodiment of the present invention so that detailed explanation will be omitted.

For convenience in explanation and accurate definition in the appended claims, the terms “upper” and “lower” are used to describe features of the exemplary embodiments with reference to the positions of such features as displayed in the figures.

The foregoing descriptions of specific exemplary embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teachings. The exemplary embodiments were chosen and described in order to explain certain principles of the invention and their practical application, to thereby enable others skilled in the art to make and utilize various exemplary embodiments of the present invention, as well as various alternatives and modifications thereof. It is intended that the scope of the invention be defined by the Claims appended hereto and their equivalents. 

1. A cam cap comprising: an oil supply circuit formed to the cam cap for supplying hydraulic pressure to a continuously variable valve timing; and an oil flowing backward preventing unit disposed to the oil supply circuit for preventing operation oil from flowing backward.
 2. The cam cap of claim 1, wherein the oil flowing backward preventing unit comprises: a flowing backward preventing hole that comprises an inlet channel for supplying the hydraulic pressure and an outlet channel for exhausting the hydraulic pressure from the inlet channel and is disposed to the oil supply circuit; and a flowing backward preventing member disposed in the flowing backward preventing hole and selectively blocking the flowing backward preventing hole according to a flow direction of the operation oil.
 3. The cam cap of claim 2, wherein the flowing backward preventing member includes a plunger provided with a chamber therein and at least an oil opening is formed to a side of the plunger for supplying a backward hydraulic pressure into the camber so as to move the plunger into the inlet channel when a backward flow of the operation oil occurs in the flowing backward preventing hole.
 4. The cam cap of claim 2, wherein the flowing backward preventing member comprises a plunger having a main body and a protrude portion protruded from the main body, the plunger being movably disposed in the flowing backward preventing hole such that the protrude portion selectively blocks the inlet channel according to a flow direction of the operation oil.
 5. The cam cap of claim 4, wherein the protrude portion protrudes from the main body with a predetermined thickness in a radial direction of the main body.
 6. The cam cap of claim 5, wherein the plunger is provided with a chamber therein and at least an oil opening is formed to a lateral side of the protrude portion to communicate with the camber with the flow backward preventing hole therethrough for supplying a backward hydraulic pressure into the camber when a backward flow of the operation oil occurs.
 7. The cam cap of claim 6, wherein the plunger includes an upper opening formed on an upper portion of the plunge to communicate the chamber with the flow backward preventing hole therethrough.
 8. The cam cap of claim 7, wherein an auxiliary flow channel is formed at a junction portion of the inlet channel and the outlet channel and supply the backward hydraulic pressure to the chamber through the upper opening.
 9. The cam cap of claim 5, wherein the plunger is provided with a chamber therein and includes an upper opening formed on an upper portion of the plunge to communicate the chamber with the flow backward preventing hole therethrough.
 10. The cam cap of claim 9, wherein an auxiliary flow channel is formed at a junction portion of the inlet channel and the outlet channel and supply the backward hydraulic pressure to the chamber through the upper opening.
 11. The cam cap of claim 4, wherein a lower end portion of the main body is shaped of a cone for smoothly supplying the hydraulic pressure between the inlet and outlet channels.
 12. The cam cap of claim 2, wherein the inlet channel and the outlet channel of the flowing backward preventing hole are substantially vertical to each other.
 13. The cam cap of claim 2, wherein a check valve for preventing the hydraulic pressure from being supplied from the outlet channel to the inlet channel is disposed to the flowing backward preventing portion.
 14. A cam cap comprising: an oil supply circuit formed to the cam cap for supplying hydraulic pressure to a continuously variable valve timing; an oil control valve disposed to the cam cap to selectively supply operation oil to the continuously variable valve timing; a flowing backward preventing hole that comprises an inlet channel for supplying the hydraulic pressure and an outlet channel for exhausting the hydraulic pressure from the inlet channel and is disposed to the oil supply circuit; and a flowing backward preventing member disposed in the flowing backward preventing hole and selectively blocking the flowing backward preventing hole according to a flow direction of the operation oil.
 15. The cam cap of claim 14, wherein the inlet channel and the outlet channel of the flowing backward preventing hole are substantially vertical to each other.
 16. The cam cap of claim 14, wherein the flowing backward preventing member includes a plunger provided with a chamber therein and at least an oil opening is formed to a side of the plunger for supplying a backward hydraulic pressure into the camber so as to move the plunger into the inlet channel when a backward flow of the operation oil occurs in the flowing backward preventing hole.
 17. The cam cap of claim 16, wherein the plunger includes a main body and a protrude portion protruded from the main body, the plunger being movably disposed in the flowing backward preventing hole such that the protrude portion selectively blocks the inlet channel according to a flow direction of the operation oil.
 18. The cam cap of claim 17, wherein a lower end portion of the main body is shaped of a cone for smoothly supplying the hydraulic pressure between the inlet and outlet channels.
 19. The cam cap of claim 14, wherein a check valve, for preventing the hydraulic pressure from supplied from the outlet channel to the inlet channel, is disposed to the flowing backward preventing portion. 